Hybrid image-pupil optical reformatter

Abstract

A hybrid image-pupil optical reformatter and method for optional use with a spectrometer is disclosed, which performs beam slicing in pupil space and stacks replicas of the input source generated from the pupil beam slices in image space. The optical reformatter comprises a collimator which receives an input light and produces a collimated beam; a first optical element which receives the collimated beam, redirects portions of the collimated beam back toward the collimator as reimaged beams and permits portions of the collimated beam to pass; a second optical element which receives the reimaging beams and redirects the reimaging beams back toward the collimator and the first optical element; to form an output beam comprising the portions of the collimated beams that are not redirected toward the collimator by the first optical element. Also disclosed is the use of the reformatter for reformatting the input light of a spectrometer system, and the use of the reformatter as part of a spectrometer device.

The invention claimed is: 
     
       1. A spectrometer comprising:
 an optical reformatter for generating an output beam, comprising: 
 a collimator which receives an input light and produces a first collimated beam; 
 a first optical element which 
 (i) redirects one or more portions of the first collimated beam so they are received by the collimator which produces one or more reimaging beams; and 
 (ii) allows one or more portions of the first collimated beam to pass by the first optical element to form part of the output beam; 
 a second optical element which redirects one or more portions of the reimaging beams so they are received by the collimator which produces additional collimated beams; 
 wherein one or more portions of the additional collimated beams also form part of the output beam; 
 an optical element to expand the output beam along a first dimension to produce an expanded beam; 
 a dispersive element to spectrally disperse the expanded beam along the first dimension to produce a spectrally dispersed beam; 
 a focusing element to Focus the spectrally dispersed beam to produce a focused spectrum; and 
 a detector to receive and measure the focused spectrum. 
 
     
     
       2. A method of generating an output beam comprising: collimating an input light using a collimator to produce a first collimated beam;
 using an optical element to redirect one or more portions of the first collimated beam so they are received by the collimator which produces one or more reimaging beams; 
 using an optical element to redirect one or more of the reimaging beams so they are received by the collimator which produces additional collimated beams; and 
 forming an output beam from the additional collimated beams and portions of the first collimated beams which are not redirected so they are received by the collimator. 
 
     
     
       3. The method of  claim 2  wherein portions of the additional collimated beams are also redirected so they are received by the collimator which produces additional reimaging beams, and one or more of the additional reimaging beams are redirected so they are received by the collimator which produces further collimated beams;
 wherein the output beam includes portions of the further additional collimated beams. 
 
     
     
       4. The method of  claim 3  wherein the redirection is iterative. 
     
     
       5. The method of  claim 2  wherein the redirected beams and beam portions are redirected to produce an output beam formed from substantially overlapping beams and beam portions, propagating in substantially the same direction, and with substantially all of the light energy in the input light. 
     
     
       6. The method of  claim 2  wherein the redirected beams and beam portions are redirected to produce an output beam that is narrower in a first dimension relative to the first collimated beam. 
     
     
       7. The method of  claim 2  further comprising focusing the output beam onto the input of a spectrometer. 
     
     
       8. The method of  claim 2  further comprising:
 expanding the output beam along a first dimension to produce an expanded beam; 
 spectrally dispersing the expanded beam along the first dimension to produce a spectrally dispersed beam; 
 focusing the spectrally dispersed beam to produce a focused spectrum, and; measuring the focused spectrum.